code: def test_split_data_by_none_label(model_data: RasaModelData):
      model_data.label_key = None
      model_data.label_sub_key = None
  
      split_model_data = model_data.split(2, 42)
  
      assert len(split_model_data) == 2
  
      train_data = split_model_data[0]
      test_data = split_model_data[1]
  
      # train data should have 3 examples
      assert len(train_data.get("label", "ids")[0]) == 3
      # test data should have 2 examples
      assert len(test_data.get("label", "ids")[0]) == 2
  
file_path: rasa/tests/utils/tensorflow/test_model_data.py
imports: import copy
  import pytest
  import numpy
  from rasa.utils.tensorflow.model_data import RasaModelData
label_desc: Use image node_id 3 for calling a global function with example usage: test_split_data_by_none_label(model_data) without return types